Standalone and self-contained cooling systems using compressed liquid and/or gas CO.sub.2 containers positioned in an insulated or non-insulated vessel encompassing a container which is either vertically positioned in an upright or an upside-down position.

The liquid and/or gas CO.sub.2 coolant is then released into a capillary system or flow metering system to allow the CO.sub.2 to enter a second body to where the CO.sub.2 coolant properties may be leveraged. The second body includes, by way of example, a plate, a cushion, a spot treatment pad for a person's muscle, or a cooler.

The temperature is controlled by a metering CO.sub.2 releasing system encompassing an electronic control device which sends alerts when pre-defined thresholds are exceeded.

The invention's metering CO.sub.2 releasing system may be triggered by an electronic or a thermostatic valve or may be triggered manually or by an electronic solenoid.

A pressure relief valve with a stop disposed thereon to ensure components of the pressure relief valve are properly aligned and tightened properly. This allows the components and pressure relief valve to be properly installed and the pressure relief valve to function properly. The stop feature also reduces the time of installation and amount of labor needed to install pressure relief valves and their components.

Standalone and self-contained cooling systems using compressed liquid and/or gas CO.sub.2 containers positioned in an insulated or non-insulated vessel encompassing a container which is either vertically positioned in an upright or an upside-down position. The liquid and/or gas CO.sub.2 coolant is then released into a capillary system or flow metering system to allow the CO.sub.2 to enter a second body to where the CO.sub.2 coolant properties may be leveraged. The second body includes, by way of example, a plate, a cushion, a spot treatment pad for a person's muscle, or a cooler. The temperature is controlled by a metering CO.sub.2 releasing system encompassing an electronic control device which sends alerts when pre-defined thresholds are exceeded. The invention's metering CO.sub.2 releasing system may be triggered by an electronic or a thermostatic valve or may be triggered manually or by an electronic solenoid.

The present invention provides a pressure relief and recovery loop, a carbon dioxide refrigeration system and a control method thereof. The pressure relief and recovery loop includes: a gas storage reservoir (110), which is used for storing gas-phase carbon dioxide; a pressure relief flow passage (120), which is used for connecting the gas storage reservoir and an associated carbon dioxide refrigeration system, and is used for discharging the gas-phase carbon dioxide in the carbon dioxide refrigeration system into the gas storage reservoir; and a recovery flow passage (130), which is used for connecting the gas storage reservoir and the associated carbon dioxide refrigeration system, and on which a driving apparatus (131) is arranged, the recovery flow passage being used for recovering the gas-phase carbon dioxide in the gas storage reservoir into the carbon dioxide refrigeration system under the drive of the driving apparatus.

A method and a test chamber for conditioning air, in which the test chamber comprises a temperature-insulated test space, which is closable to an environment and serves for receiving test material, and a temperature control device for controlling the test space in temperature, a temperature ranging from 40 C. to +180 C. being generable within the test space by the temperature control device. The temperature control device comprises a heating apparatus and a cooling apparatus having a cooling cycle, the cooling cycle having a refrigerant, a heat exchanger disposed in the test space, a compressor, a condenser and an expansion element, the refrigerant being a hydrocarbon or a refrigerant mixture made of hydrocarbons. A stop element is disposed in the cooling cycle downstream of the heat exchanger and upstream of the compressor, the stop element being able to stop reflux of refrigerant in the heat exchanger in the opposite direction of flow.

A refrigeration apparatus includes a refrigerant circuit including a utilization unit. The utilization unit includes: a heat exchanger; a first refrigerant pipe and a second refrigerant pipe connected to the heat exchanger; and a first shutoff valve and a second shutoff valve whose opening degrees are adjustable and which are respectively provided at the first refrigerant pipe and the second refrigerant pipe. The refrigeration apparatus includes: a refrigerant leakage detector; a refrigerant pressure acquiring part; and a controller configured to adjust the opening degrees of the first shutoff valve and the second shutoff valve. In an alert state where the first shutoff valve and the second shutoff valve are both closed and the refrigerant leakage detector detects the leakage, the controller adjusts the opening degree of at least one of the first shutoff valve and the second shutoff valve to open when the pressure of the refrigerant is greater than a predetermined threshold value.

A transcritical R-744 refrigeration system with a medium temperature section having a plurality of circuits, at least one evaporator receiving an R-744 refrigerant in a medium-pressure liquid state from a receiver and feeding at least one transcritical compressor to compress the R-744 refrigerant from a low-pressure gaseous state into a high-pressure gaseous state to feed a gas cooler and a throttling device to partially condense the R-744 refrigerant into a medium-pressure gaseous-liquid state, the system comprising a pressure reducing valve connected to a discharge conduit of the at least one transcritical compressor and feeding hot gas to a defrost manifold to defrost one of the plurality of circuits of the medium temperature section, wherein the hot gas being fed to the defrost manifold has a pressure value less than or equal to a maximum operating pressure of the at least one evaporator.

Provided is a heat pump device capable of discharging air in a heat medium circuit regardless of the height of the positions of two bodies, and capable of preventing a refrigerant from flowing out into a body not housing a liquid heat exchanger when the refrigerant enters the heat medium circuit in the liquid heat exchanger. To achieve this, the heat pump device includes: a refrigerant pipe connecting a compressor, a decompressor, an air heat exchanger, and a liquid heat exchanger circularly; a heat medium pipe connecting the liquid heat exchanger and a pump circularly; first and second air vent valves capable of discharging gas in the heat medium pipe to the outside; a first body housing the compressor, the decompressor, the air heat exchanger, the liquid heat exchanger, the refrigerant pipe, and the first air vent valve; and a second body housing the second air vent valve. The pump causes the liquid heat medium to flow in a predetermined circulatory direction in the heat medium pipe, and the liquid heat exchanger, the first air vent valve, and the second air vent valve are arranged in this order along the circulatory direction.

A heat pump apparatus includes: a refrigerant circuit configured to circulate refrigerant having flammability; a heat medium circuit configured to allow a heat medium to flow therethrough; a heat-medium heat exchanger configured to exchange heat between the refrigerant and the heat medium; an outdoor unit configured to accommodate the refrigerant circuit and the heat-medium heat exchanger; and an indoor unit configured to accommodate a part of the heat medium circuit, the outdoor unit including a refrigerant release valve, the refrigerant release valve being at least one of a pressure relief valve and an air purge valve which are provided in the heat medium circuit, the refrigerant release valve being provided outside a casing of the outdoor unit.

A system includes a heat exchanger coupled to an air conditioning system, and a flash tank is coupled to refrigeration cases, and houses a first refrigerant. The system includes solenoid valves coupled to the flash tank, where the solenoid valves reduce a pressure of the first refrigerant flowing from the flash tank to the heat exchanger. The heat exchanger may be coupled to the solenoid valves, and the heat exchanger may be configured to receive an amount of the first refrigerant from the solenoid valves, receive a second refrigerant from the air conditioning system, where the second refrigerant is associated with an air conditioning load, and provide cooling to the second refrigerant, using the first refrigerant. Finally, the system includes a check valve coupled to the flash tank, where the check valve reduces a pressure of the first refrigerant flowing from the flash tank away from the solenoid valves.